Sleep and Respiratory Parameters After Lung Transplantation in Adult Patients With Cystic Fibrosis

Objective: We aimed to explore the prevalence and predictive factors of sleep-disordered breathing (SDB) in patients with cystic fibrosis (pwCF) after lung transplantation (LTX). Methods: We prospectively recruited adult pwCF who underwent LTX in our hospital from 2013 to 2022 and invited them for an attended overnight polysomnography (PSG) 1 year after transplantation. The apnea-hypopnea index (AHI) was the primary outcome, and SDB was defined as an AHI >= 5. Demographic, anthropometric, cardiometabolic, drug treatment, and pulmonary function variables were compared between pwCF with and without SDB. Multiple regression analysis was used to identify significant predictors of SDB. For a subset of participants who had available PSG before transplantation, sleep parameters were compared pre-post transplantation. Results: Sixty-two pwCF (31 females) were enrolled. Thirty participants had SDB, but only 11 of them had moderate-to-severe SDB (AHI >= 15). The average Epworth Sleepiness Scale (ESS) score indicated the absence of excessive daytime sleepiness. Older age (p < 0.001), male sex (p < 0.001), and smaller thoracic gas volume (p = 0.002) significantly predicted higher AHI. Comparison between pre- and post-transplantation polysomnographic data showed a significant increase in the percentage of slow wave sleep (p = 0.047), as well as a significant improvement in mean nocturnal oxygen saturation (p = 0.007). A statistically significant increase in the AHI was also observed (p = 0.047), but its clinical importance is uncertain (p = 0.476 for the increase in the ESS score). Conclusions: We may conclude that SDB is prevalent in pwCF after LTX, but its severity is mild. Older male pwCF with greater improvement in lung hyperinflation after transplantation might be at risk for SDB and should be followed for symptoms or signs of sleep apnea.